These photos were made on the surface of Mars by the two NASA Mars Rovers, Spirit and Opportunity, which landed there in December '03 and January '04. The Rovers use stereoscopic cameras which record a pair of images, left and right, for each photo. The raw photos are available on the JPL/NASA website.
As I was looking at the photos on the NASA site I realized that many of them were stereoscopic pairs. I downloaded one of the pairs to see if I could manipulate it and make a viewable red/blue 3-D image from it. I opened the pair of images in Photoshop and fiddled with the colors. Then I combined the two images into one and voila! I had a cool 3-D anaglyph image. So, I did the same with a few more and put them here for you to see. What I like about these pictures is that they give you a much stronger sense of "being there" than you can get from the normal "flat" pictures. Mars becomes a more real place for you once you've looked at it in 3-D!
3-D Images and Depth Perception
We see in three-dimensions because of binocular vision. Each eye sees a slightly different image because they are in slightly different positions. The brain combines the two images, interpreting the differences in the images to provide us with a perception of depth. Any "3-D" image contains two images, one meant to be seen by the left eye and one meant for the right.
The images on this site use color to isolate the two images. This is called an "anaglyph" image. The image meant to be viewed by the left eye is rendered in blue and the one for the right is rendered in red. When the left eye looks through the red filter of the 3-D glasses it cannot see the red "right" image because the red filter masks it. The red filter also makes the blue image slightly darker and sifts the color to make it nearly gray. The effect of the blue filter for the right eye is the same, but in reverse. The overall result is that each eye sees only the image intended for it. The image the left eye sees is the one captured by the left half of the stereoscopic camera and the right eye sees the image from the right half. For more information about stereoscopic vision and 3-D images click here.
You need red/blue (anaglyph) 3-D glasses to view these images. If you done have a pair you can get a free pair from:
They have a bunch of cool 3-D images on their site, including some more Mars images.
Rainbow SymphonyOr, you can buy a pair from:
TIM'S TRADING POST for $2.95 (free shipping.) You can also find more Mars imasges here.
Having trouble seeing the images?
If you are having trouble getting the two images to resolve into a clear picture try this. First, relax. Don't try to see the 3-D effect. It is just a matter of focusing in the right place. Now close one eye and then open it and close the other. Blink back and forth between the two eyes. Notice how the picture seems to jump back and forth. What you are seeing is the difference between the views seen by the left and right eyes. Now try focusing your attention past the screen as though the image is receding into your monitor. Pick one item, like a rock or a mountain and focus on it. This will work for most of the images, but some of them do not recede into the monitor, but appear in front of the screen. This is especially so in the case of the 3rd and 16th images - close-ups of the rocky ground. If you have trouble seeing these images try this. Hold up a finger about 8" in front of the screen and focus on it. You should notice that the photo now seems to "click in." Keep your focus at this distance from the screen as you remove your finger. The image will jump out at you from the screen.